[tex]\displaystyle\\
\text{II)}\\
\text{II.1)}\\
f:\{-2,~1\}\to R,~~f(x)=-x+3\\
f(-2)=-(-2)+3=2+3=5\\
f(1)=-1+3=2\\
\text{II.2)}\\
g:R\to R,~~g(x)=mx-4,~m\in R\\
g(3)=5\\
m\cdot 3 - 4 = 5\\
3m-4=5\\
3m=5+4\\
3m=9\\\\
m= \frac{9}{3} =3
[/tex]
[tex]\displaystyle\\
\text{II.3)}\\
f(x)=ax+b\\
A(2,~-1)\in G_f\\
B(-1,~2)\in G_f\\
\text{Inlocuim coordonatele punctelor in functie si obtinem un sistem}\\
\text{de 2 ecuatii cu necunoscutele a si b.}\\
\begin{cases}
a\cdot 2+b=-1\\
a\cdot(-1)+b=2
\end{cases}\\\\
\begin{cases}
2a+b=-1\\
-a+b=2~~\Big| \cdot (-1)
\end{cases}\\\\
\begin{cases}
2a+b=-1\\
a-b=-2
\end{cases}~~~~\text{\}Adunam ecuatiile.}\\\\
3a=-3\\\\
a=\frac{-3}{3}=\boxed{\bf -1}\\\\
-1-b=2\\
-b=2+1\\
-b=3\\
b=\boxed{\bf -3}\\
\boxed{\bf f(x)=-x-3}[/tex]
